The tank is finally ready for some more live stock! I have had a betta and oto in there for about 2.5 weeks and all of the levels look good and stable. So I just put in 3 Cardinal Tetras and 1 Assassin Snail (didn't clean one of the driftwood pieces well enough and have a small infestation of snails).

After doing a lot of research I'm going with the following, but do have a question about my "centerpiece fish". See below.

School #1:
11 total
Cardinal Tetras

School #2:
11 total
Rummy Nose Tetras
(I'm also very much into cars, so I especially dig them because their tails look like checkered flags)